In residential and light commercial construction, it is common practice to provide, either in a poured concrete foundation wall or in a constructed block foundation wall, a ventilator opening to allow air circulation beneath the building structure. Many workable ventilators have been developed thru the years for such applications.
However, it would still be quite desirable to reduce the overall costs which must necessarily be incurred in the manufacture and distribution of such ventilators. Also, labor saving techniques, or changes in the apparatus which would reduce the cost of installation, would be welcome by the contractors charged with installing such ventilators.
We are aware of various attempts in which an effort has been made to provide an improved foundation ventilator. One of the designs which resembles the instant invention to some remote extent is disclosed by Crofoot, in U.S. Pat. No. 3,822,462, issued May 31, 1977, for VENT FRAMES. He shows a foundation ventilator which is fastened together from two identical hollow frame sections. However, he does not provide a design which includes the feature of interlocking flanges for "one-way" mating engagement of frame sections, nor does his method of fastening provide an overhanging lip joined to an underlying ledge to effectively prevent concrete slurry from entering the interior of the vent through the assembly joint, as is provided in our novel foundation ventilator. Thus, the advantages of our simple multi-part foundation ventilator, which is made with interlocking frame members that are designed for assembly in a pre-selected width, to provide a strong, substantially leak resistant through-wall ventilator, are important and self evident.